Carbon electrode for arc lamps



Patented Oot. 10, 1893.

Y J. M. LAooM-BE. CARBON ELEGTRDDE POB ARG'LAMPS.

(No -Model.)

Y l iff/2726256610:

- lUNTTED STATES PATENT OFFICE.,

JOSEPH MAURICE LACOMBE, OF PARIS, FRANCE, ASSIGNOR OF ONE-HALF TO LOUIS G. DREYFUS, OE SANTA BARBARA, CALIFORNIA.

CARBONELECTRODE FOR ARC LAMPS.

SPECIFICATION forming part of Letters Patent No. 506,650, dated October 10, 1893.

Application filed August 27, 1892. Serial 110.444,302. (No model.) Patented in France May 14, 1889, No. 198,220; in England .Tune 1,1889, No. 9,133; in Belgium September 13. 1889, No. 87,715, and in Germany September 20, 1889, No. 54,240.

To all whom it may concern.-

Be it known that I, JOSEPH MAURICE LA- ColnBE, a citizen of the Republic of France, residing at 11 Rue Barye,Paris, in the Department of Seine, France, have invented certain new and useful Improvements in the Manufacture of Carbons or Electrodes for Electric Lamps, (for which Letters Patent have been granted in France, No. 198,220, dated May 14,

1o 1889; in Great Britain, No. 9,133, dated June 1, 1889; in Germany, No. 54,240, dated September20, 1889, and in Belgium, No. 87,715,

dated September 18, 1889;) and I do herebydeclare thatthe following is a full, clear, and 15 exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to the manufacture of carbons or electrodes for electric lamps. 2o The said invention is chiefly designed to increase the efficiency of carbons or electrodes made in the form of plates, sectors or disks, which, while occupying but a small space in the lamp, contain a large volume of carbon for the maintenance of the electric arc. My improvements are, however, also applicable rto the manufacture of other forms of carbons,

although I prefer the disks'above mentioned which are intended to be arranged in pairs in 3o combination with convenient devices for rotating them about their axes so as to change the portions of their surfaces between which the arc is formed, gradually until the whole 'of both circumferences has been used to any 3 5 fixed depth and a fresh rotation started, and

so on until the disks have been so far consumed as to render it impracticable to use them further.

In the manufacture of carbons or electrodes according to the present invention, I piace between disks or other pieces or layers of carbon, a layer of a material composed of a mixture of carbonaceous and silicious substances, or any suitable composition or material which, while not interfering with the proper Working of the lamp, insures the retention of the arc in a fixed position, and the consequent steadiness of the light. The pieces or layers of carbon, with the steadying substance above 5 O mentioned between them, are preferably subjected to a high degree of compression, so as to consolidate the mass and increase the density and homogeneity thereof and the duration of the electrodes.

I am aware that attempts have been made to employ disks of carbon for arc lights, but these attempts have failed, among other reasons for the want of xity of the arc owing to the non-employment of a steadying substance such as that herein referred to. By 6o the present invention, however, plate or disk carbons can be manufactured with which a fixed or stable arc and therefore a steadyv light can be maintained.

I am also aware that carbon pencils have heretofore been `manufactured which are pierced with an axial opening and have inserted therein a mixture of refractory earth and plumbago. These carbon pencils are, however, manufactured by forcing the carbon through 7o va die, in the center of which is placed a mandrel, the steadying substance being either introduced through, or by means of a hollow mandrel, or inserted after the formation of the carbon tube. It is evident that this method of making cored carbons is not so "favorable to efficient compression of the carbons, and the density.

In making my improved carbons or elec-.8o trodes, I apply the above mentioned steadying substance or composition in a liquid or in a pasty condition, or in 'the form of powder, or I mold it to the desired shape before placing it between the two pieces or layers of carbon, according to the method adopted for the manufacture of my improved carbons or electrodes.

Among the different methods which may be adopted for the manufacture of these elec- 9o trodes,'the following aregiven by Way of examples, viz:

According to one method, one of the two elementary disks or other pieces which are to constitute the electrode, is first made by miX- ing powdered carbon with suitable adhesive or agglutinating material and slightly compressing it. This disk or other piece is then covered with a layer of the above mentioned obtaining of a high degree of steadyng substance or composition." The Ioo second disk or other piece prepared in the same manner as the first, is then placed above it, and the whole is subjected to heavypressure, preferably in a suitable mold. The electrode is then baked in the ordinary manner.

According to another method, I place in a suitable mold, a layer of carbon, together with any suitable binding or agglutinating material, and I cover this layer of carbon with the steadying substance or composition in a liquid or in a pasty condition or in the form of powder;I then place thereon another layer of carbon mixed with the adhesive material or agglutinant,and I cause an intimate union of the two layers of carbon and the intervening steadying substance or composition, by subjecting the whole to pressure in the said mold, or in any other convenient manner, the electrode being baked in the usual manner.

My invention is illustrated in the accompanying drawings, in which- Figure lis a central section of adisk carbon made by either of the above described methods. Fig. 2 is a side elevation of two of my carbon electrodes placed in juxtaposition for use in a lamp; and Fig. 3 is an edge elevation of the same.

In the drawings A represents the carbon disks and B the steadying composition interposed between them, the carbon disks and the steadying substance being brought into intimate union with each other as hereinbefore described. It is obvious, however, that the manner of combining the said substance or composition with the pieces of carbon may be modified if desired.

Although I prefer to mold my said plate or disk carbons or electrodes under pressure, yet it is obvious that, in making my carbons or electrodesI may employ any means by which the parts above mentioned may be united, for instance, chemical reaction, adhesive material, or bakingwith or without the application of pressure. I also sometimes form a spiral or coil of carbon and, after extending the same in a plastic state, I place the above mentioned steadyin g substance between the convolutions thereof, and I then compress Athe'said spiral lengthwise in any convenient manner so as to form a cylindrical or other piece having the steadying substance extending helically around the same. I thus produce an electrode which can be conveniently employed in combination with a carbon rod or other suitable electrode.

Having now particularly described and ascertained the nature ot' my said invention and in what manner the same is to be performed, I Wish it understood that I do not claim generally orl irrespectively of my improvements herein described, the employment in a carbon or electrode, of a steadying material or composition, as I am aware that, in some cases, carbons have been made with a core of vitreous or other material in order to insure steadiness of the light; but

I clairn- 1. Acarbon or electrode composed of plates or disks of carbon arranged side by side and having between them a steadying substance or composition such as I have hereinbefore described, the whole being united by pressure or otherwise, for the purpose above specified.

2. The improved method of manufacturing carbons or electrodes for electric arc lamps, consisting in first slightly compressing carbon mixed with a suitable binding or agglutinating material and thus forming one of the elementary diskor other pieces, then covering one side of the said disk or other piece with a layer of the steadying substance or composition and placing thereon the second disk or other piece prepared in the same manner as the first, and then subjecting the whole to heavy pressure, and baking it, substantially as hereinbefore described.

3. Theimproved methodof manufacturing carbons or electrodes for electric arc lamps, consisting in placing in a suitable mold, a layer or carbon mixed with binding or agglutinating material, covering this layer with the steadying substance or composition and placing thereon asimilar layer of carbon and then uniting the whole by pressure or otherwise, substantially as hereinbefore described.

. JOSEPH MAURICE LACOMBE. Witnesses:

M. M. BAIR,

RoB'r. M. I-looPER, 

